"Be a part of it," Castor said. "We are confident we can keep this a safe place and secure event and we want our citizens to be able to participate."

Catching a glimpse of history will have its challenges. Many of the roads near the Tampa Convention Center and Forum, including the lower level of the Selmon Expressway, will be shut down before the convention begins on Aug. 27 and remain closed until after the event ends on Aug. 30.

While most of downtown will be open to pedestrians, much of the area south of Brorein Street to the waterfront will be closed to all but those with convention-issued credentials.

The plan shows some changes beginning in Tampa as early as Friday, Aug. 24, and continuing through the following Friday.

The restrictions include road closures and other security measures in St. Petersburg, where a convention kickoff party for delegates and news media is scheduled for Aug. 26 at Tropicana Field. Flight and waterway restrictions, some of which were previously released, are part of the plan.

Traffic delays should be expected on the interstates from Aug. 25 through Aug. 30 to allow motorcades to travel to and from event sites, the Secret Service said.

But grasping the full impact on downtown Tampa is yet to come. While the Secret Service made public much of its long-anticipated security plan, it would not say where and when security fences will be erected for the convention that runs from Aug. 27 to 30.

An exhaustive critique the city of St. Paul released following its 2008 Republican National Convention said the next host city would not know exactly where the security fence would be until shortly before its convention. That has proven to be true.

"We will not discuss the security to be put into place," Secret Service spokesman George Ogilvie said after the release of the Tampa area plan.

The Secret Service has solicited bids for more than 20,000 feet of various fencing types, 10,000 feet of concrete barriers and nearly a mile of bike rack barriers, all of which are expected to be deployed to defend against potential penetrators and explosives.

During previous conventions, security officials created multiple checkpoints, fences or other barriers that vehicles and pedestrians had to navigate to reach the heart of the convention area. In Tampa, the main action will be at the Forum, which will host more than 19,000 attendees, and the Tampa Bay Convention Center, which will be the working headquarters for 15,000 visiting news media.

Downtown workers and businesses have been anxiously awaiting details of the security plan for weeks.

Bryan Goodell, manager at downtown restaurant Fresh, said he isn't bothered that Franklin Street where his restaurant is located will be closed to traffic during the convention.

He figures his regular customers will avoid the congestion but hopes the visitors make up the difference and then some. He plans to stay open four hours later — until midnight — each night during the convention.

"It's better that there isn't traffic," Goodell said. "There won't be a place to park."

Sabrina Webby, manager at the Jerk Hut Downtown Café, 207 E. Twiggs St., said she's relieved her street isn't closed to motorists. Although streets adjacent to her business will be shut down to traffic, she doesn't expect that to hurt her business.

"I definitely think it's going to bring new customers," she said. "We thought this is going to be a good thing for us. It's going to increase business, visibility and exposure."

Here's a look at some of the restrictions outlined in the security plan:

Streets and parking in and around three dozen downtown Tampa blocks will be restricted beginning late on the afternoon of Friday, Aug. 24, through late Friday afternoon, Aug. 31, although some closures won't take effect until Aug. 25. Traffic patterns will change on four major arteries — Whiting and 12th streets and Ashley and Channelside drives.

The plan shows virtually all downtown streets from Whiting Street south to the waterfront will be closed to traffic.

Beginning at 12:30 a.m. Aug. 27, the day the convention begins, the Selmon Expressway will be closed between Willow Avenue and 50th Street and remain off limits until 5 a.m. Aug. 31. The elevated lanes of the Selmon will remain open. The Selmon Expressway carries about 50,000 vehicles daily between the upper and lower lanes.

Pedestrian traffic will be restricted from noon Aug. 25 through 6 a.m. Aug. 30 along a stretch extending from Bayshore Boulevard east along Brorein Street.

Access to Harbour Island will be available only via the Beneficial Bridge, with vehicles subject to security screening and delayed access during convention hours. The Platt Street Bridge that handles about 35,000 vehicles daily will be closed and pedestrian traffic on the bridge and two others serving Harbour Island will be restricted.

Routes will be changed on a dozen HART bus runs and the In-Town Trolley, and the TECO Line Streetcar routes will be interrupted in the area of the Forum and Tampa Bay Convention Center.

"HART is an alternative to downtown commuting, but current and new customers should plan in advance and allow for extra time," Hillsborough Area Regional Transit spokeswoman Marcia Mejia said. "Routes and schedules are subject to change, and service interruptions can be expected with very short notice.''